THE REACH OF WAR: THE FIGHTING; U.S. Says Soldiers in Baghdad Fired on Shiites Who Had Shot at U.S. Base

By KIRK SEMPLE; Khalid W. Hassan contributed reporting from Baghdad for this article, and an Iraqi employee of The New York Times from Najaf.

Published: August 4, 2006

American troops opened fire Thursday on a vehicle carrying armed Shiites to an anti-Israel demonstration in Baghdad, killing as many as two occupants and wounding others, officials said.

While details remained murky late Thursday, the American military command said in a statement that the occupants of the van had first fired at the watchtower of an American military base near the town of Mahmudiya.

American troops returned fire, the statement said, and more than an hour later, Iraqi troops at a checkpoint captured the van and found two dead men in the back with AK-47 and PKC assault rifles.

An official at the Interior Ministry said the vehicles' occupants were followers of the militant Shiite cleric Moktada al-Sadr, who has called for a mass demonstration on Friday against Israel's bombardment of Lebanon. Charismatic and decidedly anti-American, Mr. Sadr counts millions of disaffected poor Shiites among his constituency.

According to the ministry official, only one person was killed in the shooting, and 16 were wounded.

Mahmudiya has been a location fraught with tension for American troops in recent months. Four American soldiers and one former soldier have been accused of raping a 14-year-old girl there and killing her and three family members.

The van was passing through Mahmudiya on its way to Baghdad from the southern Shiite town of Hilla, said Sahib al-Ameri, an official in Mr. Sadr's movement.

The shooting comes at a time of rising tensions between the American military and Mr. Sadr's organization. In recent weeks, American and Iraqi forces have conducted a series of raids on bases of Mr. Sadr's restless militia, the Mahdi Army, and have arrested high-ranking militia leaders.

American commanders say they are intent on destroying the country's death squads, Sunni and Shiite alike, that have fomented the sectarian violence ravaging this country.

Mr. Sadr's militia has been blamed for many of the abductions and killings of Sunni Arabs, though officials in Mr. Sadr's organization have denied any institutional involvement in these crimes and say they are attributable to rogue elements operating beyond their control.

Thousands of Mr. Sadr's supporters from Shiite-dominated cities in southern Iraq began converging on the capital on Thursday in anticipation of the rally. They boarded buses decorated with pictures of Sheik Hassan Nasrallah, the leader of the Hezbollah militia in Lebanon, which set off the current fighting with a cross-border raid.

The Sadr supporters waved Iraqi and Hezbollah flags and chanted ''Death to America! Death to Israel!'' wire service reports said.

Israel's offensive in Lebanon is highly unpopular among Iraqis, and Mr. Sadr was among the first politicians to condemn Israel's actions publicly, warning last month that his followers would ''not sit by with folded hands before the creep of Zionism.'' He also accused the United States of culpability in the bombardments because of its close relationship with Israel.

American and Iraqi security forces were bracing for enormous crowds at the rally, which is planned for Friday afternoon in the teeming working-class neighborhood of Sadr City, the cleric's main stronghold here.

Sadr City demonstrations in the past have been intense and full of anger but generally free of violence. Israel's three-week-old offensive, however, in addition to the recent government raids against the Mahdi Army, has exacerbated anger and resentment among Mr. Sadr's followers.

In his call for the demonstration, which he issued Tuesday, Mr. Sadr seemed to anticipate violence -- by his opponents, however, not by his followers.

''I know very well the dangers of holding demonstrations in our beloved Iraq, from the enemies of God and Islam,'' he said. ''But it is our duty and our love for martyrdom and to die for the sake of God that is calling us to support truth and its people. If any of you seeks heaven, then here are the open doors. Wear your shrouds and stand up to support your struggling and patient brothers in Lebanon and Iraq.''

Mr. Sadr is among the country's most powerful politicians. In the legislative elections last December, his bloc won at least 30 of 275 parliamentary seats, making it the equal of any political party in Iraq.

His currency rose in 2004 when he led two rebellions against the Americans. Though his fighters were ultimately crushed in those conflicts, his resistance, and his defiance of an American warrant for his arrest, accorded him great status, particularly among impoverished Shiites.

Since then he has transformed his organization into one similar to Hezbollah, with an armed wing -- mainly young men ready to spring into action, Kalashnikovs in hand -- and a political movement that includes the leaders of several important ministries.

Both the Mahdi Army and Hezbollah have strong ties to Iran, and all three subscribe to a similar Shiite theology.

Buses full of supporters left Thursday from several southern cities, including Basra, Najaf and Hilla. The Associated Press reported that a convoy of about 20 buses, accompanied by police vehicles, had moved out of Basra carrying young men, many of them draped in white cloth to symbolize their willingness to die as martyrs.

Sporadic guerrilla violence continued to erupt around Iraq on Thursday. In the deadliest attack, an improvised bomb concealed in a pile of garbage exploded in central Baghdad, killing 10 people and wounding 32, the Interior Ministry official said.